Anti-valgus Heal Stabilizer

ABSTRACT

A device and method of use of the device which supports a patient’s medial tubercle and thus resisting heel bone rotation. It features a generally wedge shape component configured to be added on top of a surface at a heal region of a shoe. The wedge shape component has a height ranging from a maximum on an inner, medial heel portion and tapers to become flush with the surface at the midline of the heal region of the shoe.

BACKGROUND

For our purposes, the relevant bone of the foot are (1) the calcaneus,(2) the talus and (3) the navicular as illustrated in FIG. 1 . Thecalcaneus, also known as the heel bone, is the strongest and largestbone of the foot and is the first bone to come into contact with theweightbearing surface. The talus, or ankle bone, has lower surfaces thatarticulate with upper surfaces of the calcaneus. The navicular is theprimary arch bone.

Walking is divided into two parts. The swing phase is when the foot isin the air without any body weight acting on the foot structure. Thecontact phase is when the foot makes touches the weightbearing surface.The forces from the body above combined with the ground reaction forcesfrom below will act on the osseous structures within the foot.Ligaments, muscles, and tendons will make secondary contributions to thestability and function of the foot during stranding, walking, running,and jumping.

The outer heel is the first part of the foot to make contact duringwalking. The forces from the weightbearing surface push up against theheel and the weight from the body above pushes against the top middleportion of the heel bone, the talocalcaneal posterior facets. Theweightbearing forces continue to travel from the outer heel through thecenter of the hindfoot, to the midfoot, forefoot, and finally the bottomof the toes.

The stability and alignment of the articular surfaces of the bones ofthe hindfoot is crucial for an efficient walking cycle. An orthopedicpathology called, Recurrent Talo Tarsal Dislocation (RTTJD), is acondition where the normal stability of the hindfoot bones is lostresulting in excessive hindfoot motion. This condition, RTTJD, resultsin the partial dislocation of the ankle and heel bones. The articularjoint facets between the two bones no longer remain in constantcongruent contact.

The ankle bone is the primary deforming force. It shifts from itsnatural position on the heel bone by dropping downward, forward, andinward. The heel bone will react to the abnormal ankle bone motion byslightly rotating outward. This occurs because the forces that should beacting on the joint facets toward the back of the heel, the posteriortalocalcaneal joint, are now acting toward the inner front of the heelbone. This outward rotation, movement of the heel is referred to asvalgus, as opposed to varus where the ankle of the back of the heel isturned toward the mid-line of the body.

One of the other visible signs of RTTJD is its effect the navicular, thearch bone. The ankle bone displacement pushes against the arch bone in amanner that causes the arch bone to drop. This leads to a lowering ofthe inner arch, called a flat foot. When the ankle bone is repositionedon the heel bone, the arch bone will be in its normal position and thearch will also appear “normal.”

RTTJD is a very common pathology but, it is rarely referred to by itsorthopedic description. There have been many names given to thiscondition including flatfoot, flexible flatfoot, fallen arches, adultacquired flatfoot, and weak foot. One of the most common names is calledover-pronation or hyperpronation. The loss of stability of the hindfootbones results in the combination of foot motions called pronation. Thisis opposed to the opposite motion-position of the foot bones calledsupination. Pronation results in a weakening of the foot, whereassupination results in a strengthening of the joints of the foot. Thereshould only be a very insignificant amount of pronation as the entirebottom portion of the foot contacts the weightbearing surface. Thisallows for the foot to compensate for an uneven weightbearing surface.Supination stiffens the foot to provide a stable lever-arm for the restof the gait cycle.

RTTJD leads to an extended period of a weakened joints within the foot,over-pronation. The joints should be locked and strong to get ready forthe forces that will act on them. However, because they are in aweakened stated, the ligaments, muscles, and tendons will have excessivestrain acting on them to compensate for the excessive force. Eventually,the excessive force will take their toll due to the repetitivemicro-trauma inflicted by the thousands of steps taken every day andtens of millions of steps over the years.

One of the most common forms of treatment for over-pronation is the useof shoe modifications. Specifically, the insertion of an insert into theshoe is the first recommended treatment. These shoe inserts range fromover-the-counter generic arch supports to custom-made foot orthosis.There have been many designs and claims made of these “arch” supportsthroughout the past many decades. However, there has been one keyelement that has not been incorporated to any of the pre-existing art.

All of the present-day arch supports, whether over-the-counter orcustom-made has missed a key element in their design. The presentdevices are “arch” supports -their function is to push up against thearch. Their function is aimed at the arch bone. When someone walks withan “arch” support on their shoe that support attempts to counter thedrop of the arch bone by pushing up against it. There is no radiographicdata to show that the arch support actually prevents the arch bone fromdropping. A primary design flaw with the arch supports is that they arereactive not proactive. The arch supports try to limit navicular dropafter the navicular bone is already being force downward.

There is a naturally occurring space between the ankle and heel bonescalled the sinus tarsi. This naturally occurring osseous chamber acts asa dividing line between the forces that should be acting on the back ofthe heel against the forces that should be acting toward the front ofthe foot. The sinus tarsi is obliquely oriented to allow theweightbearing forces to stay balanced between the back of the heel andthe front of the foot. RTTJD disrupts that balance before the entirebottom of the foot touches the weightbearing surface. By the time thearch of the foot comes into contact with the “arch” support thenavicular bone has been pushed out of its normal alignment. The heelwill be turned into valgus, and the forefoot also will be forced intovalgus. Arch supports function to support the part of the foot in frontof the sinus tarsi, they have no effect to the back of the heel.

The “heel cup” portion of the arch supports is the upper top area thatcomes into contact with the heel. This area is concave from side-to-sideand front to back in all arch supports but over-the-counter andcustom-made. Some of the devices claim to have a superior “cup” shape tocontrol or counter-heel valgus, but the shape of this area is alwaysconcave both front-to-back and side-to-side. There is no data to prove a“heel-cup”, no matter the size, has any ability to prevent or reverseankle bone displacement on the heel bone.

SUMMARY OF THE INVENTION

The invention is a wedged shaped modification made to the top inner heelportion of a shoe or shoe insert for the purpose of reducing excessiveexcursion, or excessive outward, backward movement of the heel bone.

SUMMARY OF THE DRAWINGS

FIG. 1 illustrates the bones of the foot with the three bones labeled (N= Navicular; T = Talus; C = Calcaneus) that are most relevant here.

FIG. 2A is a left foot top view of a preferred embodiment of theinvention.

FIG. 2B is a left foot bottom view.

FIG. 2C is a right foot side view.

FIG. 2D is a right foot front view.

FIG. 2E is a right foot rear view.

DETAILED DESCRIPTION

In anatomic terms the invention is an Anti Valgus Heel Stabilizer (AVHS)100 as shown in FIG. 2A. The wedged shape component 120 provides theprimary corrective force. As shown in FIG. 2A, the wedge 120 is added tothe inner top portion of the heel cup area of a shoe or shoe insert. Thewedge is thicker on the inner, medial portion of the heel 140, 160 andthinner toward the center of the heel 180. The wedge begins at the backof the heel up area and extends toward the front-end of the heel. Thereare a wide range of wedge shape angles, depending on the amount of innerheel stabilizing required. In one preferred embodiment a minimum slopeis employed. The thicker portion is about 1 mm to 5 mm and tapers downto zero toward the center of the heal.

In another preferred embodiment the thicker portion is about 5 mm to 10mm and tapers down to zero toward the center of the heal.

In still another preferred embodiment, the thicker portion is about 10to 25 mm and tapers down to zero toward the center of the heal.

In each case this wedge imparts an inward force to the heal on itsmedial side.

There are two anatomic landmarks on the bottom of the heel, medial andlateral plantar tubercles. These bony projections serve as attachmentpoints to muscles and fascia. The inner medial tubercle is much largerthan the lateral tubercle. There is a reason for the difference in sizebetween the two. The smaller lateral tubercle allows for a slightinversion of the heel at heel strike. As the rest of the foot drops tothe weightbearing surface the larger inner tubercle contacts the groundhelping to redirect the weightbearing forces to the front of the foot.RTTJD alters the direction of that force causing a rotation of the backof the heel.

The function of the AVHS is to provide angular support to the medialtubercle to resist heel bone rotation. The AVHS provides support for theback area of the sinus tarsi unlike the arch support 110 that supportsthe area in front of the sinus tarsi. The AVHS is meant as an additionto the arch support so that there would be support from the inner heelto the end of the long first metatarsal bone. The addition of the AVHSwould provide proactive measure because it is altering heel mechanicsprior to the ankle bone displacement rather than acting after the anklebone has already displaced. The AVHS is function before the excessiveforces are acting on the arch bone. The combination of both will providebeneficiaries with a dual form of treatment.

What is claimed is:
 1. An anti valgus heel stabilizer, useful for supporting a patient’s medial tubercle and thus resisting heel bone rotation, comprising: a generally wedge shape component configured to be added on top of a surface at a heal region of a shoe, the wedge shape component has a height ranging from a maximum on an inner, medial heel portion and tapers to become flush with the surface at the midline of the heal region of the shoe.
 2. The anti valgus heel stabilizer as defined in claim 1, further comprising the stabilizer added to the shoe as part of a shoe insert.
 3. The anti valgus heel stabilizer as defined in claim 1, further comprising the stabilizer added to the shoe during shoe manufacture.
 4. The anti valgus heel stabilizer as defined in claim 1 wherein the wedge shape maximum height further comprises a range from 1 mm to 5 mm.
 5. The anti valgus heel stabilizer as defined in claim 1 wherein the sedge shape maximum height further comprises a range from 5 mm to 10 mm.
 6. The anti valgus heel stabilizer as defined in claim 1 wherein the sedge shape maximum height further comprises a range from 10 mm to 25 mm.
 7. A method of heel stabilization comprising the use of an anti valgus heel stabilizer of claim
 1. 